Retainer for an aerosol-generating article

ABSTRACT

A kit comprising: an aerosol generating article (2) comprising a combustible heat source (4) and an aerosol-forming substrate (10); and a retainer (300) for the aerosol generating article, the retainer comprising: a tubular body (302) having a partially-closed first end (304a) and an open second end (304b), wherein the body defines a longitudinal passage (305) extending between the first end and the second end and wherein the body comprises: a first portion (307) proximate the first end comprising a plurality of openings (306); and a second portion (309) between the first portion and the second end, wherein the body is configured to at least partially receive the aerosol-generating article in the passage such that the first portion of the body surrounds the combustible heat source of the aerosol-generating article, wherein the first end and the first portion of the body are configured such that at least about 80 percent of the exposed surface area of the combustible heat source of the aerosol-generating article remains exposed through the first end and the plurality of openings in the first portion of the body when the aerosol-generating article is received in the passage such that the first portion of the body surrounds the combustible heat source of the aerosol-generating article, and wherein the ratio of the inner diameter of the first portion of the body to the outer diameter of the exposed surface of the combustible heat source is at least about 1.1.

The present invention relates to a retainer for an aerosol-generating article, such as a heated aerosol-generating article. In particular, but not exclusively, one or more embodiments of the present invention may relate to a retainer for an aerosol-generating article in which the aerosol-generating article comprises a combustible heat source and an aerosol-forming substrate.

A number of aerosol-generating articles in which tobacco is heated rather than combusted have been proposed in the art. An aim of such ‘heated’ aerosol-generating articles is to reduce known harmful smoke constituents of the type produced by the combustion and pyrolytic degradation of tobacco in conventional cigarettes. In one known type of heated aerosol-generating article, an aerosol is generated by the transfer of heat from a combustible heat source to a physically separate aerosol-forming substrate located downstream of the combustible heat source. During use, volatile compounds are released from the aerosol-forming substrate by heat transfer from the combustible heat source and entrained in air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol that is inhaled by the user.

It is known to include a heat-conducting element around at least a rear portion of the combustible heat source and at least a front portion of the aerosol-forming substrate of the heated aerosol-generating article in order to ensure conductive heat transfer from the combustible heat source to the aerosol-forming substrate to obtain an aerosol. For example, WO-A2-2009/022232 discloses a heated aerosol-generating article comprising a combustible heat source, an aerosol-forming substrate downstream of the combustible heat source, and a heat-conducting element around and in direct contact with a rear portion of the combustible heat source and an adjacent front portion of the aerosol-forming substrate. The heat-conducting element and the aerosol-forming substrate are circumscribed by an outer wrapper of paper. In use, the front portion of the aerosol-forming substrate is heated by conduction through the abutting rear portion of the combustible heat source and the heat-conducting element.

In aerosol-generating articles in which tobacco is heated rather than combusted, the temperature attained in the aerosol-forming substrate has a significant impact on the ability to generate an acceptable aerosol. It is typically desirable to maintain the temperature of the aerosol-forming substrate within a certain range in order to optimise the aerosol delivery to a user. If the temperature of the aerosol-forming substrate drops too low, for instance, it may adversely impact the consistency and the amount of aerosol delivered to a user.

The combustible heat source of an aerosol-generating article requires a sufficient supply of air (oxygen) to permit ignition and support sustained combustion. Accordingly, any means provided for securing and retaining the combustible heat source must not overly restrict the supply of air to the combustible heat source. If the supply of air is overly restricted, sustained combustion of the combustible heat source may not be achieved during use, which may cause the temperature of the aerosol-forming substrate to drop and adversely impact the consistency and the amount of aerosol delivered to a user.

A variety of combustible carbon-containing heat sources for use in heated aerosol-generating articles have been proposed in the art. The combustion temperature of combustible carbon-containing heat sources for use in heated aerosol-generating articles is typically between about 600° C. and 800° C. Heated aerosol-generating articles comprising combustible carbon-containing heat sources can have an undesirably high ignition propensity due to the high combustion temperature of combustible carbon-containing heat sources. As used herein, the term “ignition propensity” refers to the ability or tendency of the combustible heat source to ignite other things once it has been lit. In addition, the high combustion temperature can make it difficult to extinguish the combustible heat source.

It would be desirable to provide a retainer for an aerosol-generating article comprising a combustible heat source and an aerosol-forming substrate that protects the combustible heat source during use.

It would be desirable to provide a retainer for an aerosol-generating article comprising a combustible heat source and an aerosol-forming substrate that reduces the ignition propensity of the combustible heat source during and after use.

It would be desirable to provide a retainer for an aerosol-generating article comprising a combustible heat source and an aerosol-forming substrate that facilitates extinguishment of the combustible heat source after use.

It would be desirable to provide a retainer for an aerosol-generating article comprising a combustible heat source and an aerosol-forming substrate that does not significantly adversely impact the lighting time of the combustible heat source.

It would be desirable to provide a retainer for an aerosol-generating article comprising a combustible heat source and an aerosol-forming substrate that does not significantly adversely impact the aerosol deliveries of the aerosol-generating article.

According to the present disclosure, there is provided a kit comprising: an aerosol-generating article comprising a combustible heat source and an aerosol-forming substrate; and a retainer comprising: a tubular body having a partially-closed first end and an open second end, wherein the body defines a longitudinal passage extending between the first end and the second end and wherein the body comprises: a first portion proximate the first end comprising a plurality of openings; and a second portion between the first portion and the second end, wherein the body is configured to at least partially receive the aerosol-generating article in the passage such that the first portion of the body surrounds the combustible heat source of the aerosol-generating article, wherein the first end and the first portion of the body are configured such that at least about 80 percent of the exposed surface area of the combustible heat source of the aerosol-generating article remains exposed through the first end and the plurality of openings in the first portion of the body when the aerosol-generating article is received in the passage, and wherein the ratio of the inner diameter of the first portion of the body to the outer diameter of the exposed surface of the combustible heat source is at least about 1.1.

The retainer advantageously protects the combustible heat source of the aerosol-generating article from breakage during lighting without significantly adversely impacting the lighting time of the combustible heat source. The retainer also advantageously protects the combustible heat source of the aerosol-generating article from breakage during combustion without significantly adversely impacting the aerosol deliveries of the aerosol-generating article. In the event of breakage or drop-off of the combustible heat source, the retainer retains the combustible heat source of the aerosol generating article within the body. Furthermore, the retainer advantageously protects the combustible heat source from coming into contact with other things and therefore reduces the ignition propensity of the combustible heat source during and after use.

Advantageously, an aerosol-generating article cannot be inserted or removed from the passage through the partially-closed first end. However, air can flow through the partially-closed first end to the combustible heat source to facilitate lighting and sustained combustion of the combustible heat source.

Configuring the first end and the first portion of the body such that at least about 80 percent of the exposed surface area of the combustible heat source of the aerosol-generating article remains exposed through the first end and the plurality of openings in the first portion of the body when the aerosol-generating article is received in the passage has advantageously been found to permit a sufficient air supply to the combustible heat source to enable lighting and support sustained combustion.

The ratio of the inner diameter of the first portion of the body to the outer diameter of the exposed surface of the combustible heat source is at least about 1.1. This ratio has surprisingly been found to have a positive impact on aerosol deliveries and on the temperature of the aerosol-forming substrate of the aerosol-generating article.

As used herein, the term “aerosol generating article” refers to an article comprising an aerosol-forming substrate that releases volatile compounds to form an aerosol that may be inhaled by a user. The term “aerosol-forming substrate” is used herein to refer to a substrate capable of releasing, upon heating, volatile compounds, which may form an aerosol. The aerosols generated from aerosol-forming substrates of articles according to the invention may be visible or invisible and may include vapours (for example, fine particles of substances, which are in a gaseous state, that are ordinarily liquid or solid at room temperature) as well as gases and liquid droplets of condensed vapours.

The aerosol-forming substrate may be in the form of a plug or segment comprising a material capable of releasing upon heating volatile compounds, which can form an aerosol, circumscribed by an outer wrapper. Where an aerosol-forming substrate is in the form of such a plug or segment, the entire plug or segment including the outer wrapper is considered to be the aerosol-forming substrate.

As used herein, the term “partially-closed” is used to describe an arrangement of the first end which allows air to flow through the first end to the combustible heat source but prevents insertion or removal of the aerosol-generating article from the passage through the first end. Allowing air to flow through the first end to the combustible heat source facilitates lighting and sustained combustion of the combustible heat source. For the avoidance of doubt, the term “at least partially-closed” includes an arrangement in which the first end is fully closed such that air cannot flow through the first end.

As used herein, the term “open” is used to describe an arrangement of the second end which allows insertion or removal of the aerosol-generating article from the passage through the second end.

The percentage of the exposed surface area of the combustible heat source of the aerosol-generating article that remains exposed through the first end and the plurality of openings in the first portion of the body when the aerosol-generating article is received in the passage refers to the percentage of the openings in the first portion of the body that is covering the heat source. For the avoidance of doubt, it is not the total exposed area of the combustible heat source. The percentage is calculated by considering the total external surface of the tubular body over the portion of the combustible heat source burning zone. In other words, the percentage refers to the percentage of tubular body surface that has been removed by forming the openings and partially closed first end versus the total surface of the tubular body covering the exposed surface area of the heat source.

The terms “distal”, “upstream” and “front”, and “proximal”, “downstream” and “rear”, are used to describe the relative positions of components, or portions of components, of an aerosol generating article. Aerosol generating articles according to the invention have a proximal end through which, in use, an aerosol exits the article for delivery to a user, and have an opposing distal end. The proximal end of the aerosol generating article may also be referred to as the mouth end. In use, a user draws on the proximal end of the aerosol generating article in order to inhale an aerosol generated by the aerosol generating article. The terms upstream and downstream are relative to the direction of aerosol movement through the aerosol generating article when a user draws on the proximal end. The proximal end of the aerosol-generating article is downstream of the distal end of the aerosol-generating article. The proximal end of the aerosol-generating article may also be referred to as the downstream end of the aerosol-generating article and the distal end of the aerosol-generating article may also be referred to as the upstream end of the aerosol-generating article.

In certain preferred embodiments, the first end and the first portion of the body may be configured such that between about 80 percent and about 90 percent of the exposed surface area of the combustible heat source of the aerosol-generating article remains exposed through the first end and the plurality of openings in the first portion of the body when the aerosol-generating article is received in the passage such that the first portion of the body surrounds the combustible heat source of the aerosol-generating article. This configuration has been found to provide improved air supply to the combustible heat source to enable lighting and support sustained combustion.

The ratio of the inner diameter of the first portion of the body to the outer diameter of the exposed surface of the combustible heat source may preferably be at least about 1.16, preferably between about 1.16 and about 1.6 and more preferably at least about 1.2. These preferred ratios have also surprisingly been found to have a positive impact on aerosol deliveries and on the temperature of the aerosol-forming substrate of the aerosol-generating article.

The body may be configured to at least partially receive the aerosol-generating article in the passage such that the first portion of the body surrounds the combustible heat source and the aerosol-forming substrate of the aerosol-generating article. Advantageously, by surrounding both the combustible heat source and the aerosol-forming substrate of the aerosol-generating article, air is permitted to reach not only the combustible heat source but to also enter any air inlets which may be formed in the aerosol-forming substrate section of the aerosol-generating article.

Prior to use, the aerosol-generating article may be inserted into the passage through the second end of the body. After use, the aerosol-generating article can be removed from the passage through the second end.

The passage may be configured to receive at least the combustible heat source and aerosol-forming substrate of the aerosol-generating article when the aerosol-generating article is inserted in a direction from the second end towards the first end.

The body may contact the combustible heat source of the aerosol-generating article. Preferably, contact between the first end and the combustible heat source is limited to avoid heat loss though conduction. Contact between the first end and the combustible heat source may be limited to between one and four contact points. Contact between the first end and the combustible heat source may be limited to a surface area of between 1 millimetres² and 4 millimetres².

The body may be substantially non-combustible at temperatures reached by combustible heat source during combustion and ignition. The body may be made of any suitable material or combination of materials. Preferably, the material or materials forming the body are heat resistant. For example, the body may be formed from materials that can withstand temperatures of between about 600 degrees Celsius and 800 degrees Celsius.

The body may have any suitable dimensions for at least partially receiving an aerosol-generating article comprising a combustible heat source in the passage. For example, the body may have a length from about 5.5 millimetres to about 70 millimetres inclusive. For example, the body may have an inner diameter from about 8.5 millimeters to about 12 millimetres.

The material or materials forming the first portion of the body may have a low thermal conductivity. For example, the material or materials forming the first portion of the body may have a thermal conductivity of 40 Wm⁻¹K⁻¹ or less, preferably 30 Wm⁻¹K⁻¹ or less and more preferably 20 Wm⁻¹K⁻¹ or less. Examples of suitable materials for forming the body include metals having a low thermal conductivity, such as stainless steel, and ceramics.

The first portion of the body may have any suitable thickness. For example, the first portion of the body may have a thickness from about 20 micrometres to about 300 micrometres, preferably from 100 micrometres to 250 micrometres.

The first portion of the body is configured to protect the combustible heat source. The plurality of openings in the body provide sufficient air supply to the combustible heat source to enable lighting and support sustained combustion. The plurality of openings in the body also allow combustion gases generated by the combustion of combustible heat source to escape from passage. In addition to surrounding the combustible heat source, the plurality of openings may also surround and permit airflow to the aerosol-forming substrate. The plurality of openings may surround the aerosol-forming substrate and permit airflow into the aerosol-generating article through air inlets provided in the aerosol-forming substrate.

The second portion of the body may be configured to be held by a user when the aerosol-generating article is received in the passage such that the first portion of the body surrounds the combustible heat source of the aerosol-generating article. The second portion therefore may act as a grip.

The second portion of the body may comprise a material having a low thermal conductivity. For example, the second portion of the body may comprise a material having a thermal conductivity of 0.5 Wm⁻¹K⁻¹ or less, preferably 0.4 Wm⁻¹K⁻¹ or less and more preferably 0.3 Wm⁻¹K⁻¹ or less. Advantageously, by providing a material having a low thermal conductivity, heat transfer through the second portion is reduced such that the temperature of the outer surface of the second portion is reduced and a user may comfortably hold the second portion of the body. Examples of suitable materials for forming the second portion include polyether ether ketone (PEEK) and other high temperature resistant polymers. The second portion may be made from an elastomeric material, such as silicone or polyurethane, to accommodate aerosol-generating articles of different diameters.

The second portion of the body may comprise multiple layers. The second portion of the body may comprise an outer layer having a low thermal conductivity. For example, the second portion of the body may comprise an outer layer having a thermal conductivity of 0.5 Wm⁻¹K⁻¹ or less, preferably 0.4 Wm⁻¹K⁻¹ or less and more preferably 0.3 Wm⁻¹K⁻¹ or less. Advantageously, by having an outer layer having a low thermal conductivity, heat transfer through the outer layer of the second portion is reduced such that the temperature of the outer surface of the outer layer is reduced and a user may comfortably hold the second portion of the body. Examples of suitable materials for forming the outer layer of the second portion include polyether ether ketone (PEEK) and other high temperature resistant polymers. The outer layer of the second portion may be made from an elastomeric material, such as silicone or polyurethane.

The second portion of the body may comprise an opening through which a user can contact the outer surface of the aerosol-generating article when received in the passage. This allows the user to simultaneously grip the aerosol-generating article and the retainer when an aerosol-generating article is received in the passage.

The kit may further comprise an air impermeable cap, wherein the cap is configured to fit over the first end and the first portion of the body of the retainer.

The cap advantageously facilitates extinguishment of the combustible heat source of the aerosol-generating article after use. When the air impermeable cap is fitted over the first end and the first portion of the body, the plurality of openings are covered by the cap, which inhibits combustion of the combustible heat source by restricting the air supply to the combustible heat source. This extinguishes the combustible heat source more quickly than simply allowing it to burn out.

The cap may comprise an inner layer having a high thermal conductivity. For example, the cap may comprise an inner layer having a thermal conductivity of 120 Wm⁻¹K⁻¹ or more, preferably 200 Wm⁻¹K⁻¹ or more and more preferably 280 Wm⁻¹K⁻¹ or more. Advantageously, by providing the cap with an inner layer having a high thermal conductivity, the inner layer acts as a heat sink and reduces the temperature of the combustible heat source more quickly than a cap which does not have a high thermal conductivity inner layer. Examples of suitable materials for forming the inner layer of the cap include aluminium and copper.

The cap may comprise an outer layer having a low thermal conductivity. For example, the cap may comprise an outer layer having a thermal conductivity of 0.5 Wm⁻¹K⁻¹ or less, preferably 0.4 Wm⁻¹K⁻¹ or less and more preferably 0.3 Wm⁻¹K⁻¹ or less. Advantageously, by having an outer layer having a low thermal conductivity, heat transfer through the outer layer of the cap is reduced such that the temperature of the outer surface of the cap is reduced and a user may comfortably hold the cap. Examples of suitable materials for forming the outer layer of the cap include polyether ether ketone (PEEK) and other high temperature resistant polymers. The cap may be made from an elastomeric material, such as silicone or polyurethane.

The cap may comprise one or more phase-change materials. The phase-change material may consume heat produced by the combustible heat source, thereby cooling the combustible heat source more quickly than a cap without a phase change material.

In certain preferred embodiments, the cap and the first portion of the body of the retainer may be configured to be detachably coupled to one another via a snap-fit connection. This helps to ensure correct placement of the cap on the retainer. Optionally, the snap-fit connection may produce an audible click when the cap is correctly coupled to the retainer to provide an audible indication of correct placement of the cap.

According to the present disclosure, there is provided a retainer for an aerosol-generating article comprising a combustible heat source and an aerosol-forming substrate, the retainer comprising: a tubular body having a partially-closed first end and an open second end, wherein the body defines a longitudinal passage extending between the first end and the second end and wherein the body comprises: a first portion proximate the first end comprising a plurality of openings; and an air-impermeable second portion between the first portion and the second end, wherein the body is configured to at least partially receive an aerosol-generating article comprising a combustible heat source and an aerosol-forming substrate in the passage such that the body and the aerosol-generating article are moveable longitudinally relative to one another between a first position in which the first portion of the body surrounds the combustible heat source of the aerosol-generating article and a second position in which the second portion of the body surrounds the combustible heat source of the aerosol-generating article, wherein the plurality of openings in the first portion are configured to permit airflow to the combustible heat source and the aerosol-forming substrate of the aerosol-generating article in the first position and wherein the second portion is configured to inhibit combustion of the combustible heat source of the aerosol-generating article in the second position.

The retainer advantageously protects the combustible heat source of the aerosol-generating article from breakage during lighting without significantly adversely impacting the lighting time of the combustible heat source. The retainer also advantageously protects the combustible heat source of the aerosol-generating article from breakage during combustion without significantly adversely impacting the aerosol deliveries of the aerosol-generating article. In the event of breakage or drop-off of the combustible heat source, the retainer retains the combustible heat source of the aerosol generating article within the body. Furthermore, the retainer advantageously protects the combustible heat source from coming into contact with other things and therefore reduces the ignition propensity of the combustible heat source during and after use.

Advantageously, an aerosol-generating article cannot be inserted or removed from the passage through the partially-closed first end. However, air can flow through the partially-closed first end to the combustible heat source to facilitate lighting and sustained combustion of the combustible heat source.

Another advantage of the retainer is that it facilitates extinguishment of the combustible heat source of the aerosol-generating article after use. When the body and the aerosol-generating article are in the second position, the second portion of the body surrounds the combustible heat source of the aerosol-generating article which inhibits the supply of air to the combustible heat source and extinguishes the combustible heat source more quickly than by simply allowing it to burn out.

The body may be configured to at least partially receive an aerosol-generating article comprising a combustible heat source and an aerosol-forming substrate in the passage such that the body and the aerosol-generating article are moveable longitudinally relative to one another between a first position in which the first portion of the body surrounds the combustible heat source and the aerosol-forming substrate of the aerosol-generating article and a second position in which the second portion of the body surrounds the combustible heat source of the aerosol-generating article. Advantageously, by surrounding both the combustible heat source and the aerosol-forming substrate of the aerosol-generating article, air is permitted to reach not only the combustible heat source but to also enter any air inlets which may be formed in the aerosol-forming substrate section of the aerosol-generating article.

Prior to use, the aerosol-generating article may be inserted into the passage through the second end of the body. After use, the aerosol-generating article can be removed from the passage through the second end.

The passage may be configured to receive at least the combustible heat source and aerosol-forming substrate of the aerosol-generating article when the aerosol-generating article is inserted in a direction from the second end towards the first end.

Preferably, the passage may be configured to allow slidable relative longitudinal movement of the body and the aerosol-generating article between the first position and the second position. Relative longitudinal movement of the body and the aerosol-generating article between the first position and the second position allows control of the air supply to the combustible heat source.

The body may contact the combustible heat source of the aerosol-generating article. Preferably, contact between the first end and the combustible heat source is limited to avoid heat loss though conduction. Contact between the first end and the combustible heat source may be limited to between one and four contact points. Contact between the first end and the combustible heat source may be limited to a surface area of between 1 millimetres² and 4 millimetres².

The body may be substantially non-combustible at temperatures reached by the combustible heat source during combustion and ignition. The body may be made of any suitable material or combination of materials. Preferably, the material or materials forming the body are heat resistant. For example, the body may be formed from materials that can withstand temperatures of between about 600 degrees Celsius and 800 degrees Celsius. The body may have any suitable dimensions for at least partially receiving an aerosol-generating article comprising a combustible heat source in the passage. For example, the body may have a length from about 5.5 millimetres to about 70 millimetres inclusive. For example, the body may have an inner diameter from about 8.5 millimetres to about 12 millimetres.

The material or materials forming the first portion of the body may have a low thermal conductivity. For example, the material or materials forming the first portion of the body may have a thermal conductivity of 40 Wm⁻¹K⁻¹ or less, preferably 30 Wm⁻¹K⁻¹ or less and more preferably 20 Wm⁻¹K⁻¹ or less. Examples of suitable materials for forming the body include metals having a low thermal conductivity, such as stainless steel, and ceramics.

The first portion of the body may have any suitable thickness. For example, the first portion of the body may have a thickness from about 20 micrometres to about 300 micrometres, preferably from 100 micrometres to 250 micrometres.

The first portion of the body is configured to protect the combustible heat source. The plurality of openings in the body provide sufficient air supply to the combustible heat source to enable lighting and support sustained combustion. The plurality of openings in the body also allow combustion gases generated by the combustion of combustible heat source to escape from the passage. In addition to surrounding the combustible heat source, the plurality of openings may also surround and permit airflow to the aerosol-forming substrate. The plurality of openings may surround the aerosol-forming substrate and permit airflow into the aerosol-generating article through air inlets provided in the aerosol-forming substrate.

The second portion of the body may be configured to be held by a user in the first position. The second portion is air impermeable and does not have any openings. The second portion inhibits combustion of the combustible heat source in the second position by restricting the air supply to the combustible heat source. The second portion may therefore act as an extinguishing grip.

The second portion of the body may comprise a material having a low thermal conductivity. For example, the second portion of the body may comprise a material having a thermal conductivity of 0.5 Wm⁻¹K⁻¹ or less, preferably 0.4 Wm⁻¹K⁻¹ or less and more preferably 0.3 Wm⁻¹K⁻¹ or less. Advantageously, by providing a material having a low thermal conductivity, heat transfer through the second portion is reduced such that the temperature of the outer surface of the second portion is reduced and a user may comfortably hold the second portion of the body. Examples of suitable materials for forming the second portion include polyether ether ketone (PEEK) and other high temperature resistant polymers. The second portion may be made from an elastomeric material, such as silicone or polyurethane, to accommodate for aerosol-generating articles of different diameters.

The second portion of the body may comprise multiple layers. The second portion of the body may comprise an inner layer having a high thermal conductivity. For example, the second portion of the body may comprise an inner layer having a thermal conductivity of 120 Wm⁻¹K⁻¹ or more, preferably 200 Wm⁻¹K⁻¹ or more and more preferably 280 Wm⁻¹K⁻¹ or more. Advantageously, by providing the second portion of the body with an inner layer having a high thermal conductivity, the inner layer acts as a heat sink when the body and the aerosol-generating article are in the second position. The inner layer reduces the temperature of the combustible heat source more quickly than a body which does not have a high thermal conductivity inner layer arranged in a second portion. Examples of suitable materials for forming the inner layer of the second portion of the body include aluminium and copper.

The second portion of the body may comprise an outer layer having a low thermal conductivity. For example, the second portion of the body may comprise an outer layer having a thermal conductivity of 0.5 Wm⁻¹K⁻¹ or less, preferably 0.4 Wm⁻¹K⁻¹ or less and more preferably 0.3 Wm⁻¹K⁻¹ or less. Advantageously, by having an outer layer having a low thermal conductivity, heat transfer through the outer layer of the second portion is reduced such that the temperature of the outer surface of the outer layer is reduced and a user may comfortably hold the second portion of the body. Examples of suitable materials for forming the outer layer of the second portion include polyether ether ketone (PEEK) and other high temperature resistant polymers. The outer layer of the second portion may be made from an elastomeric material, such as silicone or polyurethane.

According to the present disclosure, there is provided a kit comprising a retainer as described above and an aerosol-generating article comprising a combustible heat source and an aerosol-forming substrate.

The first end and the first portion of the body of the retainer may be configured such that at least about 80 percent of the exposed surface area of the combustible heat source of the aerosol-generating article remains exposed through the first end of the body and the plurality of openings in the first portion of the body in the first position. This arrangement has advantageously been found to permit a sufficient air supply to the combustible heat source to enable lighting and support sustained combustion.

In certain preferred embodiments, the first end and the first portion of the body may be configured such that between about 80 percent and about 90 percent of the exposed surface area of the combustible heat source of the aerosol-generating article remains exposed through the first end of the body and the plurality of openings in the first portion of the body in the first position. This configuration has been found to provide improved air supply to the combustible heat source to enable lighting and support sustained combustion.

The ratio of the inner diameter of the first portion of the body to the outer diameter of the exposed surface of the combustible heat source may be at least about 1.1, preferably at least about 1.16, more preferably between about 1.16 and about 1.6 and yet more preferably at least about 1.2. These ratios have surprisingly been found to have a positive impact on aerosol deliveries and on the temperature of the aerosol-forming substrate of the aerosol-generating article.

According to the present disclosure, there is provided a retainer for an aerosol generating article comprising a combustible heat source and an aerosol-forming substrate, the retainer comprising: a tubular body having a first end and a second end, wherein the first end is at least partially closed and the second end is open, wherein the body defines a longitudinal passage extending between the first end and the second end, wherein the body comprises a plurality of openings proximate the first end, and wherein the body is configured to at least partially receive an aerosol-generating article comprising a combustible heat source in the passage such that the plurality of openings surround the combustible heat source of the aerosol-generating article; and an open-ended air-impermeable sleeve around the tubular body, wherein the body and the sleeve are longitudinally moveable relative to one another from: a first position in which the plurality of openings in the body are not covered by the sleeve and in which removal of an aerosol-generating article received in the passage from the body through the second end is prevented; and a second position in which the plurality of openings in the body are covered by the sleeve and in which an aerosol-generating article received in the passage may be removed from the body through the second end.

The retainer advantageously protects the combustible heat source of the aerosol-generating article from breakage during lighting without significantly adversely impacting the lighting time of the combustible heat source. The retainer also advantageously protects the combustible heat source of the aerosol-generating article from breakage during combustion without significantly adversely impacting the aerosol deliveries of the aerosol-generating article. In the event of breakage or drop-off of the combustible heat source, the retainer retains the combustible heat source of the aerosol generating article within the body. Furthermore, the retainer advantageously protects the combustible heat source from coming into contact with other things and therefore reduces the ignition propensity of the combustible heat source during and after use.

Advantageously, an aerosol-generating article cannot be inserted or removed from the passage through the first end. However, air can flow through the plurality of openings to the combustible heat source to facilitate lighting and sustained combustion of the combustible heat source.

Another advantage of the retainer is that it facilitates extinguishment of the combustible heat source of the aerosol-generating article after use. When the body and the sleeve are in the second position the plurality of openings in the body are covered by the sleeve which inhibits the supply of air to the combustible heat source and extinguishes the combustible heat source more quickly than by simply allowing it to burn out.

The body may comprise a first portion proximate the first end comprising the plurality of openings and a second portion between the first portion and the second end. In the first position the sleeve may overlie the second portion of the body and in the second position the sleeve may overlie the first portion of the body.

The body and the sleeve may be longitudinally moveable relative to one another from the second position to the first position.

In the second position an aerosol-generating article comprising a combustible heat source and an aerosol-forming substrate may be inserted into the passage through the second end of the body. The aerosol-generating article may be inserted into the passage through the second end of the body prior to use. After use, the aerosol-generating article can be removed from the passage through the second end. This arrangement allows the retainer to be reused with other aerosol-generating articles.

In the first position insertion of an aerosol-generating article comprising a combustible heat source and an aerosol-forming substrate into the passage through the second end of the body may be prevented.

The retainer may comprise a retention member configured to engage an aerosol-generating article received in the passage. The retention member may be configured to engage or grip an aerosol-generating article received in the passage to prevent longitudinal movement of the aerosol-generating article relative to the body.

In certain preferred embodiments, longitudinal movement of the body and the sleeve relative to one another from the second position to the first position forces the retention member into contact with an outer surface of the aerosol-generating article. This arrangement combines the relative movement of the body and sleeve and the engagement of the aerosol-generating article into a single user action and as a result the aerosol-generating article is automatically gripped when the body and sleeve are moved to the first position.

In certain preferred embodiments, longitudinal movement of the sleeve relative to the body from the first position to the second position releases the retention member to allow longitudinal movement of the aerosol-generating article relative to the body.

The body and the sleeve may be longitudinally slidable relative to one another between the first position and the second position. This provides a simple guided movement for a user to move the body and sleeve between the first and second positions.

The body may contact the combustible heat source of the aerosol-generating article in the first position. Preferably, contact between the first end and the combustible heat source is limited to avoid heat loss through conduction. Contact between the first end and the combustible heat source may be limited to between one and four contact points. Contact between the first end and the combustible heat source may be limited to a surface area of between 1 millimetres² and 4 millimetres².

The body may be substantially non-combustible at temperatures reached by combustible heat source during combustion and ignition. The body may be made of any suitable material or combination of materials. Preferably, the material or materials forming the body are heat resistant. For example, the body may be formed from materials that can withstand temperatures of between about 600 degrees Celsius and 800 degrees Celsius. Preferably, the material or materials forming the body have a low thermal conductivity. For example, the material or materials forming the body may have a thermal conductivity of 40 Wm⁻¹K⁻¹ or less, preferably 30 Wm⁻¹K⁻¹ or less and more preferably 20 Wm⁻¹K⁻¹ or less. Examples of suitable materials for forming the body include metals having a low thermal conductivity, such as stainless steel, and ceramics.

The body may have any suitable dimensions for at least partially receiving an aerosol-generating article comprising a combustible heat source in the passage. For example, the body may have a length from about 5.5 millimetres to about 70 millimetres inclusive. For example, the body may have an inner diameter from about 8.5 millimetres to about 12 millimetres.

The body may have any suitable thickness. For example, the body may have a thickness from about 20 micrometres to about 300 micrometres, preferably from 100 micrometres to 250 micrometres.

The passage may be configured to receive at least the combustible heat source and aerosol-forming substrate of the aerosol-generating article when the aerosol-generating article is inserted in a direction from the second end towards the first end.

In the first position, the plurality of openings in the body provide sufficient air supply to the combustible heat source to enable lighting and support sustained combustion of the combustible heat source. The plurality of openings in the body also allow combustion gases generated by the combustion of combustible heat source to escape from passage. In addition to surrounding the combustible heat source, the plurality of openings may also surround and permit airflow to the aerosol-forming substrate. The plurality of openings may surround the aerosol-forming substrate and permit airflow into the aerosol-generating article through air inlets provided in the aerosol-forming substrate.

The sleeve may be substantially non-combustible at temperatures reached by the combustible heat source during combustion and ignition. The sleeve may be made of any suitable material or combination of materials. Preferably, the material or materials forming the sleeve are heat resistant. Preferably, the material or materials forming the sleeve have a low thermal conductivity. For example, the material or materials forming the sleeve may have a thermal conductivity of 0.5 Wm⁻¹K⁻¹ or less, preferably 0.4 Wm⁻¹K⁻¹ or less and more preferably 0.3 Wm⁻¹K⁻¹ or less. Examples of suitable materials for forming the sleeve include polyether ether ketone (PEEK) and other high temperature resistant polymers. The sleeve may be made from an elastomeric material, such as silicone or polyurethane, to accommodate for aerosol-generating articles of different diameters.

The sleeve may be configured to be held by a user when the body and sleeve are in the first position.

According to the present disclosure, there is provided a kit comprising: a retainer as described above and an aerosol-generating article comprising a combustible heat source and an aerosol-forming substrate.

The first end and the first portion of the body may be configured such that at least about 80 percent of the exposed surface area of the combustible heat source of the aerosol-generating article remains exposed through the first end of the body and the plurality of openings in the first portion of the body in the first position. This configuration has been found to provide a sufficient air supply to the combustible heat source to enable lighting and support sustained combustion.

In certain preferred embodiments, the first end and the first portion of the body may be configured such that between about 80 percent and about 90 percent of the exposed surface area of the combustible heat source of the aerosol-generating article remains exposed through the first end of the body and the plurality of openings in the first portion of the body in the first position. This configuration has been found to provide improved air supply to the combustible heat source to enable lighting and support sustained combustion.

The ratio of the inner diameter of the first portion of the body to the outer diameter of the exposed surface of the combustible heat source may be at least about 1.1, preferably at least about 1.16, more preferably between about 1.16 and about 1.6 and yet more preferably at least about 1.2. These ratios have surprisingly been found to have a positive impact on aerosol deliveries and on the temperature of the aerosol-forming substrate of the aerosol-generating article.

The retainers for an aerosol-generating article described herein may comprise a thermal indicator to provide one or more of: a visual sign to a user of when to commence use of the aerosol-generating article; a visual sign to a user of when to cease use of the aerosol-generating article; and a visual sign to a user of when the combustible heat source of the aerosol-generating article is extinguished and sufficiently cool for the aerosol-generating article to be disposed of.

The thermal indicator may be provided on an outer surface of the body. The thermal indicator may be provided at a location on the body which overlies the combustible heat source when an aerosol-generating article is received in the passage. The thermal indicator may be provided on an outer surface of the cap or the sleeve.

The thermal indicator may comprise at least one reversible thermochromic material that undergoes a reversible visible colour change when the temperature of the thermal indicator rises or falls to a switching temperature.

As used herein with reference to the invention, the term “thermochromic material” is used to describe any material that undergoes a visible colour change at a predetermined switching temperature. Thermochromic materials may undergo a visible colour change as the temperature rises or falls over a transition range. As used herein with reference to the invention, the term “switching temperature” is used to describe the temperature at which the visible colour change of a thermochromic material is complete. The switching temperature may be determined by measuring the colour intensity of the thermochromic material.

The thermochromic material may undergo a first reversible visible colour change when the temperature of the thermal indicator rises to a first switching temperature at which aerosol deliveries will be generated and provide a visual sign to a user that they can commence use of the aerosol-generating article. When the thermal indicator is at a temperature below the first switching temperature, it provides a visual sign to a user that they should not commence or should cease use of the aerosol-generating article.

The thermochromic material may undergo a second reversible visible colour change when the temperature of the thermal indicator falls to a second switching temperature at which combustion of the combustible heat source cannot be sustained and provide a visual sign to a user that the combustible carbonaceous heat source is extinguished and sufficiently cool for the aerosol-generating article to be disposed of.

The first switching temperature may be at least about 200 degrees Celsius, preferably at least about 250 degrees Celsius, and more preferably at least about 300 degrees Celsius.

The second switching temperature may be less than about 150 degrees Celsius, preferably less than about 100 degrees Celsius, and more preferably less than about 80 degrees Celsius.

The thermal indicator may include any suitable reversible thermochromic material. For example, the thermal indicator may comprise one or more materials selected from the group consisting of reversible thermochromic liquid crystals, reversible thermochromic inorganic materials (for example, metal complexes), reversible thermochromic organic materials (for example, leuco dyes) and combinations thereof.

Suitable liquid crystals include, but are not limited to, cholesteryl esters (for example, cholesteryl nonanoate) and cyanobiphenyls. Suitable leuco dyes include, but are not limited to, spirolactones (for example, fluorans and crystal violet lactone), spiropyran, and fulgides. Retainers according to the present invention may be used with any suitable aerosol-generating article having a combustible heat source.

The combustible heat source is located at or proximate to the distal end of the aerosol-generating article. The combustible heat source has a front end face and an opposed rear end face. The front end face of the combustible carbonaceous heat source is at the upstream end of the combustible carbonaceous heat source. The upstream end of the combustible carbonaceous heat source is the end of the combustible carbonaceous heat source furthest from the proximal end of the aerosol-generating article. The rear end face of the combustible carbonaceous heat source is at the downstream end of the combustible carbonaceous heat source. The downstream end of the combustible carbonaceous heat source is the end of the combustible carbonaceous heat source closest to the proximal end of the aerosol-generating article.

An aerosol-generating article for use with a retainer according to the present invention may comprise any suitable combustible heat source.

Aerosol-generating articles according to the invention may comprise a non-blind combustible heat source.

As used herein with reference to the invention, the term “non-blind” is used to describe a combustible heat source including at least one airflow channel extending from the front end face to the rear end face of the combustible heat source.

As used herein with reference to the invention, the term “airflow channel” is used to describe a channel extending along the length of a combustible heat source through which air may be drawn for inhalation by a user.

Aerosol-generating articles according to the invention comprising a non-blind combustible heat source may comprise a non-combustible substantially air impermeable barrier between the non-blind combustible heat source and the one or more airflow channels. The barrier between the non-blind combustible heat source and the one or more airflow channels may be adhered or otherwise affixed to the non-blind combustible heat source.

Advantageously, the barrier comprises a non-combustible substantially air impermeable barrier coating provided on an inner surface of the one or more airflow channels. In such embodiments, advantageously the barrier comprises a barrier coating provided on at least substantially the entire inner surface of the one or more airflow channels. More advantageously, the barrier comprises a barrier coating provided on the entire inner surface of the one or more airflow channels.

Aerosol-generating articles according to the invention may comprise a blind combustible heat source.

As used herein with reference to the invention, the term “blind” is used to describe a combustible heat source that does not include any airflow channels extending from the front end face to the rear end face of the combustible heat source.

As used herein with reference to the invention, the term “blind” is also used to describe a combustible heat source including one or more airflow channels extending from the front end face of the combustible heat source to the rear end face of the combustible heat source, wherein a non-combustible substantially air impermeable barrier between the rear end face of the combustible heat source and the aerosol-forming substrate barrier prevents air from being drawn along the length of the combustible heat source through the one or more airflow channels.

Aerosol-generating articles according to the invention comprising blind combustible heat sources comprise one or more air inlets downstream of the rear end face of the combustible heat source for drawing air into the aerosol-generating article.

The combustible heat source is preferably a carbonaceous heat source having a carbon content of at least about 35 percent, more preferably of at least about 40 percent, most preferably of at least about 45 percent by dry weight of the combustible heat source. Where the combustible heat source is a carbonaceous heat source, the combustible heat source may be formed from one or more suitable carbon-containing materials. The term “carbonaceous” refers to a material that comprises carbon.

The combustible heat source may be a combustible carbon-based heat source having a carbon content of at least about 50 percent. For example, the combustible heat source may be a combustible carbon-based heat source having a carbon content of at least about 60 percent, or at least about 70 percent, or at least about 80 percent by dry weight of the combustible heat source. The term “carbon-based” refers to a material comprises primarily of carbon or at least about 50% carbon, by dry weight of material.

One or more binders may be combined with the one or more carbon-containing materials to form the carbonaceous heat source. The combustible heat source may comprise one or more organic binders, one or more inorganic binders or a combination of one or more organic binders and one or more inorganic binders.

Instead of, or in addition to one or more binders, the combustible heat source may comprise one or more additives in order to improve the properties of the combustible heat source. Suitable additives include, but are not limited to, additives to promote consolidation of the combustible heat source (for example, sintering aids), additives to promote ignition of the combustible heat source (for example, oxidisers such as perchlorates, chlorates, nitrates, peroxides, permanganates, zirconium and combinations thereof), additives to promote combustion of the combustible heat source (for example, potassium and potassium salts, such as potassium citrate) and additives to promote decomposition of one or more gases produced by combustion of the combustible heat source (for example catalysts, such as CuO, Fe₂O₃ and Al₂O₃). Combustible heat sources for aerosol generating articles and methods for producing such heat sources are known in the art and described in, for example, U.S. Pat. Nos. 5,040,552 and 5,595,577.

The combustible heat source may comprise at least one ignition aid. Advantageously, the combustible heat source may comprise at least one ignition aid as described in WO-A1-2012/164077.

The combustible heat source may be formed by a pressing process or an extrusion process. Preferably, the combustible carbonaceous heat source is formed by a pressing process.

Preferably, the combustible heat source has an apparent density of between about 0.8 grams/centimeter³ and about 1.1 grams/centimeter³. Preferably, the combustible heat source has a mass of between about 300 milligrams and about 500 milligrams, more preferably of between about 400 milligrams and about 450 milligrams. Preferably, the combustible heat source has a length of between about 7 millimetres and about 17 millimetres, more preferably of between about 7 millimetres and about 15 millimetres, yet more preferably of between about 7 millimetres and about 13 millimeters, and most preferably of about 9 millimetres. Preferably, combustible heat sources according to the invention have a width of between about 5 millimetres and about 9 millimetres, more preferably of between about 7 millimetres and about 8 millimetres.

Preferably, the combustible heat source is of substantially uniform diameter. However, the combustible heat source may alternatively be tapered such that the diameter of one of the front end face and the rear end face of the combustible heat source is greater than the diameter of the other of the front end face and the rear end face thereof. For example, combustible heat sources may be tapered such that the diameter of the rear end face of the combustible heat source is greater that the diameter of the front end face of the combustible heat source. Preferably, the combustible heat source is substantially cylindrical. The combustible heat source may be a cylindrical combustible heat source of substantially circular cross-section or of substantially elliptical cross-section. In particularly preferred embodiments, the combustible heat source is a substantially cylindrical combustible heat source of substantially circular cross-section.

An aerosol generating article for use with a retainer according to the invention may include any aerosol-forming substrate.

The aerosol-forming substrate may be a solid aerosol-forming substrate. The solid aerosol-forming substrate may comprise, for example, one or more of: powder, granules, pellets, shreds, spaghetti strands, strips or sheets of material capable of releasing volatile compounds in response to heating. The solid aerosol-forming substrate may be in loose form, or may be provided in a suitable container or cartridge.

The aerosol-forming substrate may comprise both solid and liquid components.

Preferably, the aerosol-forming substrate comprises at least one aerosol-former and a material capable of releasing volatile compounds in response to heating. The aerosol-forming substrate may comprise other additives and ingredients including, but not limited to, humectants, flavorants, binders and mixtures thereof. Preferably, the aerosol-forming substrate comprises nicotine. More preferably, the aerosol-forming substrate comprises tobacco.

The at least one aerosol-former may be any suitable known compound or mixture of compounds that, in use, facilitates formation of a dense and stable aerosol and that is substantially resistant to thermal degradation at the operating temperature of the aerosol-generating article. Suitable aerosol-formers are well known in the art and include, for example, polyhydric alcohols, esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate, and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Preferred aerosol formers for use in aerosol-generating articles according to the invention are polyhydric alcohols or mixtures thereof, such as triethylene glycol, 1,3-butanediol and, most preferred, glycerine.

The material capable of emitting volatile compounds in response to heating may be a charge of plant-based material. The material capable of emitting volatile compounds in response to heating may be a charge of homogenised plant-based material. For example, the aerosol-forming substrate may comprise one or more materials derived from plants including, but not limited to: tobacco; tea, for example green tea; peppermint; laurel; eucalyptus; basil; sage; verbena; and tarragon.

Advantageously, the material capable of emitting volatile compounds in response to heating is a charge of tobacco-based material, most advantageously a charge of homogenised tobacco-based material.

The aerosol-forming substrate may be in the form of a plug or segment comprising a material capable of emitting volatile compounds in response to heating circumscribed by an outer wrapper of paper or other material. As stated above, where an aerosol-forming substrate is in the form of such a plug or segment, the entire plug or segment including any outer wrapper is considered to be the aerosol-forming substrate.

Advantageously, the aerosol-forming substrate may comprise a plug of tobacco-based material wrapped in a plug wrap. More advantageously, the aerosol-forming substrate may comprise a plug of homogenised tobacco-based material wrapped in a plug wrap.

Preferably, the aerosol-forming substrate has a length of between about 5 millimetres and about 20 millimetres, more preferably of between about 6 millimetres and about 15 millimetres, yet more preferably of between about 7 millimetres and about 12 millimetres and most preferably of about 9 millimetres.

The aerosol-forming substrate may be located within, around or downstream of the combustible carbonaceous heat source. Advantageously, the aerosol-forming substrate is downstream of the combustible carbonaceous heat source.

In embodiments in which the aerosol-forming substrate is downstream of the combustible carbonaceous heat source, the thermal indicator may be provided on an outer surface of the aerosol-generating article overlying the aerosol-forming substrate

In embodiments in which the combustible carbonaceous heat source is a blind combustible heat source and the aerosol-forming substrate is downstream of the blind combustible carbonaceous heat source, advantageously aerosol-generating articles according to the invention comprise one or more air inlets around the periphery of the aerosol-forming substrate. More advantageously, in such embodiments aerosol-generating articles according to the invention comprise one or more air inlets located proximate to the downstream end of the aerosol-forming substrate.

Aerosol generating articles described herein may comprise one or more heat conducting elements around at least a rear portion of the combustible carbonaceous heat source and at least a front portion of the aerosol-forming substrate.

In embodiments in which the aerosol-forming substrate is downstream of the combustible carbonaceous heat source, aerosol-generating articles according to the invention may advantageously comprise a heat-conducting element around and in direct contact with both at least a rear portion of the combustible carbonaceous heat source and at least a front portion of the aerosol-forming substrate. In such embodiments, the heat-conducting element provides a thermal link between the combustible carbonaceous heat source and the aerosol-forming substrate and advantageously helps to facilitate adequate heat transfer from the combustible carbonaceous heat source to the aerosol-forming substrate to provide an acceptable aerosol.

Aerosol-generating articles according to the invention may comprise a heat-conducting element spaced apart from one or both of the combustible carbonaceous heat source and the aerosol-forming substrate, such that there is no direct contact between the heat-conducting element and one or both of the combustible carbonaceous heat source and the aerosol-forming substrate.

Advantageously, the one or more heat-conducting elements are non-combustible.

The one or more heat conducting elements may be oxygen restricting. In other words, the one or more heat-conducting elements may inhibit or resist the passage of oxygen through the heat-conducting element.

Suitable heat-conducting elements for use in aerosol-generating articles according to the invention include, but are not limited to: metal foil wrappers such as, for example, aluminium foil wrappers, steel wrappers, iron foil wrappers and copper foil wrappers; and metal alloy foil wrappers.

In embodiments in which the aerosol-forming substrate is downstream of the combustible carbonaceous heat source, aerosol-generating articles according to the invention may advantageously further comprise a non-combustible substantially air impermeable barrier between the rear end face of the combustible carbonaceous heat source and the aerosol-forming substrate.

As used herein with reference to the invention, the term “non-combustible” is used to describe a barrier that is substantially non-combustible at temperatures reached by the combustible carbonaceous heat source during combustion and ignition thereof.

The barrier may abut one or both of the rear end face of the combustible carbonaceous heat source and the aerosol-forming substrate. Alternatively, the barrier may be spaced apart from one or both of the rear end face of the combustible carbonaceous heat source and the aerosol-forming substrate.

As used herein with reference to the invention, the term “abut” is used to describe a component, or portion of a component, being in direct contact with another component, or portion of a component.

The barrier may be adhered or otherwise affixed to one or both of the rear end face of the combustible carbonaceous heat source and the aerosol-forming substrate.

Advantageously, the barrier comprises a non-combustible substantially air impermeable barrier coating provided on the rear end face of the combustible carbonaceous heat source. In such embodiments, advantageously the barrier comprises a barrier coating provided on at least substantially the entire rear end face of the combustible carbonaceous heat source. More advantageously, the barrier comprises a barrier coating provided on the entire rear end face of the combustible carbonaceous heat source.

Aerosol-generating articles described herein may comprise a mouthpiece located at the proximal end thereof. Preferably, the mouthpiece is of low filtration efficiency, more preferably of very low filtration efficiency. The mouthpiece may be a single segment or component mouthpiece. Alternatively, the mouthpiece may be a multi-segment or multi-component mouthpiece.

The mouthpiece may comprise a filter comprising one or more segments comprising suitable known filtration materials. Suitable filtration materials are known in the art and include, but are not limited to, cellulose acetate and paper. Alternatively or in addition, the mouthpiece may comprise one or more segments comprising absorbents, flavorants, and other aerosol modifiers and additives or combinations thereof.

Aerosol-generating articles described herein may further comprise a transfer element or spacer element between the aerosol-forming substrate and the mouthpiece. The transfer element may abut one or both of the aerosol-forming substrate and the mouthpiece. Alternatively, the transfer element may be spaced apart from one or both of the aerosol-forming substrate and the mouthpiece.

The inclusion of a transfer element advantageously allows cooling of the aerosol generated by heat transfer from the combustible heat source to the aerosol-forming substrate. The inclusion of a transfer element also advantageously allows the overall length of the aerosol-generating article to be adjusted to a desired value, for example to a length similar to that of a conventional cigarette, through an appropriate choice of the length of the transfer element.

The transfer element may have a length of between about 7 millimetres and about 50 millimetres, for example a length of between about 10 millimetres and about 45 millimetres or of between about 15 millimetres and about 30 millimetres. The transfer element may have other lengths depending upon the desired overall length of the aerosol-generating article, and the presence and length of other components within the aerosol-generating article.

Preferably, the transfer element comprises at least one open-ended tubular hollow body. In such embodiments, in use, air drawn into the aerosol-generating article passes through the at least one open-ended tubular hollow body as it passes downstream through the aerosol-generating article from the aerosol-forming substrate to the mouthpiece. The transfer element may comprise at least one open-ended tubular hollow body formed from one or more suitable materials that are substantially thermally stable at the temperature of the aerosol generated by the transfer of heat from the combustible heat source to the aerosol-forming substrate. Suitable materials are known in the art and include, but are not limited to, paper, cardboard, plastics, such a cellulose acetate, ceramics and combinations thereof.

Alternatively or in addition, aerosol-generating articles described herein may comprise an aerosol-cooling element or heat exchanger between the aerosol-forming substrate and the mouthpiece. The aerosol-cooling element may comprise a plurality of longitudinally extending channels. The aerosol-cooling element may comprise a gathered sheet of material selected from the group consisting of metallic foil, polymeric material, and substantially non-porous paper or cardboard. In certain embodiments, the aerosol-cooling element may comprise a gathered sheet of material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), and aluminum foil. Preferably the aerosol-cooling element may comprise a gathered sheet of biodegradable polymeric material, such as polylactic acid (PLA) or a grade of Mater-Br® (a commercially available family of starch based copolyesters).

The aerosol-generating articles described herein may comprise an outer wrapper that circumscribes the aerosol-forming substrate and at least a rear portion of the heat source. The outer wrapper should grip the heat source and the aerosol-forming substrate of the aerosol-generating article when the aerosol generating article is assembled. Preferably the outer wrapper circumscribes the aerosol-forming substrate, at least a rear portion of the heat source and any other components of the aerosol-generating article downstream of the aerosol-forming substrate. Outer wrappers may be formed from any suitable material or combination of materials. Suitable materials are well known in the art and include, but are not limited to, cigarette paper. Alternatively or in addition, the mouthpiece may be circumscribed by tipping paper.

Aerosol generating articles described herein may be assembled using known methods and machinery.

The aerosol-generating article may be substantially cylindrical in shape. The aerosol-generating article may be substantially elongate. The aerosol-forming substrate may be substantially cylindrical in shape. The aerosol-forming substrate may be substantially elongate. The aerosol-forming substrate may be located in the aerosol-generating article such that the length of the aerosol-forming substrate is substantially parallel to the airflow direction in the aerosol-generating article. The transfer element may be substantially elongate.

The aerosol-generating article may have any desired length. For example, the aerosol generating article may have a total length of between approximately 65 millimetres and approximately 100 millimetres, more preferably between approximately 65 millimetres and approximately 80 millimetres and most preferably of approximately 70 millimetres. The aerosol-generating article may have any desired external diameter. For example, the aerosol generating article may have an external diameter of between approximately 5 millimetres and approximately 12 millimetres, more preferably of between approximately 6 millimetres and approximately 9 millimetres, and most preferably of approximately 7.8 millimetres.

Features described in relation to one or more embodiments or examples of the present disclosure may equally be applied to other embodiments or examples of the invention.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic longitudinal cross-section of an aerosol-generating article for use with a retainer according to the invention.

FIG. 2 is a perspective view of a retainer according to an embodiment of the present invention together with an aerosol-generating article received within the retainer.

FIG. 3 is perspective view of a tubular body of the retainer of FIG. 2 .

FIG. 4 shows a longitudinal cross-section of the retainer of FIG. 2 together with an aerosol-generating article received within the retainer.

FIG. 5A is a longitudinal cross-section of a retainer according to another embodiment of the present invention showing an aerosol-generating article received within the retainer and a sleeve of the retainer in a first position.

FIG. 5B is a longitudinal cross-section of a retainer according to another embodiment of the present invention showing an aerosol-generating article received within the retainer and a sleeve of the retainer in a second position.

FIG. 6 is a perspective view of a retainer according to another embodiment of the present invention.

FIG. 7 shows the retainer of FIG. 6 together with an aerosol-generating article received within the retainer.

FIG. 8A shows a cap for the retainer of FIG. 6 .

FIG. 8B is a longitudinal cross-section of the cap of FIG. 8A.

FIG. 9 shows the cap of FIG. 8A attached to the retainer of FIG. 6 together with an aerosol-generating article received within the retainer.

FIG. 10 is a perspective view of a retainer according to another embodiment of the present invention.

FIG. 11A is a side view of a retainer similar to that of FIG. 10 together with an aerosol-generating article received within the retainer in which the retainer is located in a first position.

FIG. 11B is a side view of a retainer similar to that of FIG. 10 together with an aerosol-generating article received within the retainer in which the retainer is located in a second position.

FIG. 12 is a perspective view of a retainer according to another embodiment of the present invention together with an aerosol-generating article received within the retainer.

FIGS. 13A to 13C are perspective views of alternative patterns for the tubular body of a retainer according to the invention.

FIG. 13D is a perspective view of another pattern for the tubular body of a retainer.

FIG. 14 is a graph showing the impact of the diameter of the tubular body on the temperature of the aerosol-forming substrate for four example retainers according to the invention.

FIG. 15 is a graph showing the lack of impact of the thickness of the tubular body on the temperature of the aerosol-forming substrate for four different example retainers.

Referring now to FIG. 1 , there is shown a schematic longitudinal cross-section of an aerosol-generating article for use with a retainer according to the present invention.

The aerosol-generating article 2 shown in FIG. 1 comprises a combustible carbonaceous heat source 4 having a front end face 6 and an opposed rear end face 8, an aerosol-forming substrate 10, a transfer element 12, an aerosol-cooling element 14, a spacer element 16 and a mouthpiece 18 in abutting coaxial alignment. As shown in FIG. 1 , the aerosol-forming substrate 10, transfer element 12 and a rear portion of the combustible heat source 4 are wrapped in a co-laminated outer wrapper 20. The co-laminated outer wrapper 20 comprises an inner layer of paper and an outer layer of aluminium foil (not shown).

The combustible carbonaceous heat source 4 is a cylindrical blind carbonaceous combustible heat source and is located at the distal end of the aerosol-generating article 2. As shown in FIG. 1 , a non-combustible substantially air impermeable barrier 22 in the form of a disc of aluminium foil is provided between the rear end face 8 of the combustible carbonaceous heat source 4 and the aerosol-forming substrate 10. The barrier 22 is applied to the rear end face 8 of the combustible carbonaceous heat source 4 by pressing the disc of aluminium foil onto the rear end face 8 of the combustible carbonaceous heat source 4 and abuts the rear end face 8 of the combustible carbonaceous heat source 4 and the aerosol-forming substrate 10.

The aerosol-forming substrate 10 is located immediately downstream of the barrier 22 applied to the rear end face 8 of the combustible carbonaceous heat source 4. The aerosol-forming substrate 10 comprises a cylindrical plug of homogenised tobacco-based material 24 including glycerine as an aerosol former wrapped in plug wrap 26.

The transfer element 12 is located immediately downstream of the aerosol-forming substrate 10 and comprises a cylindrical open-ended hollow cellulose acetate tube 28.

The aerosol-cooling element 14 is located immediately downstream of the transfer element 12 and comprises a gathered sheet of biodegradable polymeric material such as, for example, polylactic acid.

The spacer element 16 is located immediately downstream of the aerosol-cooling element 14 and comprises a cylindrical open-ended hollow paper or cardboard tube.

The mouthpiece 18 is located immediately downstream of the spacer element 16. As shown in FIG. 1 , the mouthpiece 18 is located at the proximal end of the aerosol-generating article 2 and comprises a cylindrical plug of suitable filtration material 30 such as, for example, cellulose acetate tow of very low filtration efficiency, wrapped in filter plug wrap.

The aerosol-generating article 2 further comprises a band of tipping paper 38 that circumscribes the mouthpiece 18, aerosol-cooling element 14, the spacer element 16 and a downstream end portion of the outer wrapper 20 overlying the transfer element 12.

As shown in FIG. 1 , the aerosol-generating article 2 further comprises a heat-conducting element 34 of aluminium foil around and in direct contact with a rear portion 4 b of the blind combustible heat source 4 and a front portion 10 a of the aerosol-forming substrate 10.

The aerosol-generating article 2 according to the invention shown in FIG. 1 comprises one or more first air inlets 36 around the periphery of the aerosol-forming substrate 10. As shown in FIG. 1 , a circumferential arrangement of first air inlets 36 is provided in the plug wrap 26 of the aerosol-forming substrate 10 and the overlying outer wrapper 20 to admit cool air (shown by dotted arrows in FIG. 1 ) into the aerosol-forming substrate 10.

In use, a user ignites the combustible carbonaceous heat source 4. Once the combustible carbonaceous heat source 4 is ignited the user draws on the mouthpiece 18 of the aerosol-generating article 2. When a user draws on the mouthpiece 18, cool air (shown by dotted arrows in FIGS. 1 ) is drawn into the aerosol-forming substrate 10 of the aerosol-generating article 2 through the first air inlets 36.

The front portion 10 a of the aerosol-forming substrate 10 is heated by conduction through the rear end face 8 of the combustible carbonaceous heat source 4 and the barrier 22 and the heat-conducting element 34. The heating of the aerosol-forming substrate 10 by conduction releases glycerine and other volatile and semi-volatile compounds from the plug of homogenised tobacco-based material 24. The compounds released from the aerosol-forming substrate 10 form an aerosol that is entrained in the air drawn into the aerosol-forming substrate 10 of the aerosol-generating article 2 through the first air inlets 36 as it flows through the aerosol-forming substrate 10. The drawn air and entrained aerosol (shown by dashed arrows in FIG. 1 ) pass downstream through the interior of the cylindrical open-ended hollow cellulose acetate tube 28 of the transfer element 12, the aerosol-cooling element 14 and the spacer element 16, where they cool and condense. The cooled drawn air and entrained aerosol pass downstream through the mouthpiece 18 and are delivered to the user through the proximal end of the aerosol-generating article 2. The non-combustible substantially air impermeable barrier 22 on the rear end face 8 of the combustible carbonaceous heat source 4 isolates the combustible carbonaceous heat source 4 from air drawn through the aerosol-generating article 2 such that, in use, air drawn through the aerosol-generating article 2 does not come into direct contact with the combustible carbonaceous heat source 4.

After use of the aerosol-generating article 2, the user extinguishes the combustible heat source 4 of the aerosol-generating article 2.

FIG. 2 shows a perspective view of a retainer 100 according to an embodiment of the present invention and an aerosol-generating article 2 comprising a combustible heat source 4 which is received within the retainer 100. The retainer 100 comprises a tubular body 102 having a closed first end 104 a. The body 102 comprises a first portion 107 proximate the first end 104 a that comprises a plurality of openings 106 for permitting air to reach the combustible heat source 4. The body 102 is configured to receive the aerosol-generating article 2 such that the plurality of openings 106 surround the combustible heat source 4 of the aerosol-generating article 2.

The first portion 107 of the body 102 is configured such that at least about 80 percent of the exposed surface area of the combustible heat source 4 of the aerosol-generating article 2 remains exposed through the plurality of openings 106 in the first portion 107 of the body 102 in the first position. The body 102 has a substantially circular cross-section and is made from stainless steel. The diameter of the body 102 is greater than the diameter of the aerosol-generating article 2 such that the ratio of the inner diameter of the first portion 107 of the body 102 to the outer diameter of the exposed surface of the combustible heat source 4 is at least about 1.2.

The retainer 100 further comprises an open-ended air-impermeable sleeve 108 which is arranged around the tubular body 102. The body 102 and the sleeve 108 are longitudinally moveable relative to one another from: a first position in which the plurality of openings 106 in the body 102 are not covered by the sleeve 108 and in which removal of the aerosol-generating article 2 from the body 102 through the second end is prevented; and a second position in which the plurality of openings 106 in the body 102 are covered by the sleeve 108 and in which the aerosol-generating article 2 may be removed from the body 102 through the second end.

FIG. 3 shows the body 102 of the retainer 100 of FIG. 2 without the sleeve 108. In addition to a first end 104 a and a first portion 107, the body 102 further comprises an open second end 104 b and a second portion 109 arranged between the first portion 107 and the second end 104 b. A retention member 110 is attached to the open second end 104 b. The retention member 110 is annular in shape and is made from PEEK to resist the high temperatures encountered by the body 102. The retention member 110 is attached to the body 102 by over-moulding and comprises a plurality of resilient fingers 112 which extend longitudinally outwardly beyond the second end 104 b of the body. The fingers 112 of the retention member 110 have protrusions 114 arranged at their tips which protrude radially outwards and are configured to engage a complementary protrusion (not shown) arranged on an inner surface of the sleeve 108 shown in FIG. 2 .

FIG. 4 shows a longitudinal cross-section of the retainer 100 of FIG. 2 and an aerosol-generating article 2 received within the retainer 100. As can be seen from FIG. 4 , the body 102 defines a longitudinal passage 105 extending between the first end 104 a and the second end 104 b of the body 102. The aerosol-generating article 2 is received within the passage 105 of the body 102 such that the plurality of openings 106 surround the combustible heat source 4 of the aerosol-generating article 2.

The sleeve 108 can slide longitudinally in the direction of arrow A in FIG. 4 towards the first position in which the plurality of openings 106 in the body 102 are not covered by the sleeve 108 and in which removal of the aerosol-generating article 2 received in the passage 105 from the body 102 through the second end 104 b is prevented. The sleeve 108 can also slide longitudinally in a direction opposite to that of arrow A towards the second position in which the plurality of openings 106 in the body 102 are covered by the sleeve 108 and in which the aerosol-generating article 2 received in the passage 105 may be removed from the body 102 through the second end 104 b. The body 102 and the sleeve 108 are therefore longitudinally slidable relative to one another between the first position and the second position. In the first position, the sleeve 108 overlies the second portion 109 of the body 102 and in the second position the sleeve 108 overlies the first portion 107 of the body 102.

In FIG. 4 , the sleeve 108 is in the process of being slid longitudinally in the direction of arrow A towards the first position. The complementary protrusion 116 formed on the inner surface of the sleeve 108 is about to engage the protrusions 114 formed on the finger 112 of retention member 100. When the complementary protrusion 116 on the inner surface of the sleeve 108 is brought into engagement with the protrusions 114 formed on the fingers 112 of the retention member 110 by the longitudinal movement of the sleeve 108, the fingers 112 are depressed radially inwards to contact the aerosol-generating article 2. The fingers 112 of the retention member 110 grip and hold the aerosol-generating article 2 in the body 102 and prevent the aerosol-generating article 2 from being removed from the body 102 when the sleeve 108 is in the first position. The retention member 110 therefore acts as a chuck for gripping and holding the aerosol-generating article 2. Furthermore, when the sleeve 108 is in the second position, insertion of an aerosol-generating article into the body 102 is prevented due to the reduced radial dimensions of the second end 104 b.

Engagement of the complementary protrusion 116 and protrusions 114 prevents further movement of the sleeve 108 in the direction of arrow A and prevents removal of the sleeve 108 from the body 102 when the sleeve 108 is in the first position. A further protrusion 118 arranged at a proximal end of the sleeve 108 on an inner surface of the sleeve 108 prevents removal of the sleeve from the body in the opposite direction to arrow A when the sleeve 108 is in the second position.

FIGS. 5A and 5B show longitudinal cross-sections of a retainer 200 according to another embodiment of the present invention in which an aerosol-generating article is received within the retainer and a sleeve of the retainer is shown in first and second positions respectively. The retainer 200 of FIGS. 5A and 5B is similar to that shown in FIGS. 2 to 4 with the exception that the retention member 210 is tubular rather than annular and extends further towards a proximal end of the aerosol-generating article 2.

FIG. 5A shows the sleeve 208 in a first position in which the plurality of openings 206 in the body 202 are not covered by the sleeve 208 and in which removal of the aerosol-generating article 2 received in the passage from the body 102 through the second end 204 b is prevented. The complementary protrusion 216 on the inner surface of the sleeve 208 has engaged the protrusions 214 on the retention member 210 forcing the retention member into contact with the aerosol-generating article 2 to grip the aerosol-generating article 2 and prevent it being removed through the open end 204 b. In the first position, air is free to reach the combustible heat source 4 of the aerosol-generating article 2, which underlies the openings 206 in the body 202, so that the combustible heat source 4 can be ignited and combustion can be sustained.

FIG. 5B shows the sleeve 208 in a second position in which the plurality of openings 206 in the body 202 are covered by the sleeve 208 and in which the aerosol-generating article 2 received in the passage 205 may be removed from the body 202 through the second end 204 b. In the second position, the amount of air reaching the combustible heat source 4 of the aerosol-generating article 2 is significantly reduced because the sleeve 208 is covering the openings 206 in the body 202 and air cannot enter through the closed first end 204 a of the body 202. The amount of air reaching the combustible heat source 4 is not sufficient to sustain combustion. The sleeve 208 can therefore be slid into the second position to extinguish the aerosol-generating article 2. Furthermore, in the second position, the complementary protrusion 216 on the inner surface of the sleeve 208 has been disengaged from the protrusions 214 on the retention member 210 such that the retention member is no longer forced into contact with the aerosol-generating article 2 and the aerosol-generating article 2 can be removed through the open end 204 b once the combustible heat source 4 is extinguished.

In use, a retainer 100, 200 of FIGS. 2 to 4 and 5A and 5B can be provided either preloaded with an aerosol-generating article 2 with the sleeve 108, 208 in the first position or an aerosol-generating article can be inserted through the open end 104 b, 204 b of the body 102, 202 when the sleeve 108, 208 is in the second position and the sleeve 108, 208 then moved to the first position to hold the aerosol-generating article. Indicia may be printed or formed on the outer surface of the aerosol-generating article to indicate correct positioning of the aerosol-generating article 2 in the retainer 100, 200.

A user holds the combination of the retainer 100, 200 and the aerosol-generating article 2 by the sleeve 108, 208 between their fingers and ignites the tip of the combustible heat source 4 through the plurality of openings 106, 206 formed in the body 102, 202. Once the combustible heat source 4 has been ignited, a user can take puffs on the aerosol-generating article 2. A thermochromic ink or coating may be applied to the outer surface of the body 102, 202 to indicate to a user when the combustible heat source 4 is at a temperature at which puffs can be commenced.

Once a user has finished taking puffs, the combustible heat source 4 can be extinguished by moving the sleeve 108, 208 from the first position to the second position such that the plurality of openings 106, 206 in the body 102, 202 are covered by the sleeve 108, 208. Once the combustible heat source 4 has been extinguished, the aerosol-generating article 2 can be removed from the retainer 100, 200 and safely disposed of. A thermochromic ink or coating may be applied to the outer surface of the sleeve 108, 208 to indicate when the temperature of the combustible heat source has dropped to a temperature indicative of the combustible heat source having been extinguished. The retainer may be kept for use with another aerosol-generating article.

FIG. 6 is a perspective view of a retainer 300 for an aerosol-generating article according to another embodiment of the present invention. The retainer 300 comprises a tubular body 302 having a partially-closed first end 304 a and an open second end 304 b. A longitudinal passage 305 for receiving an aerosol-generating article extends between the first end 304 a and the second end 304 b. The passage 305 is configured to receive an aerosol-generating article through the second end 304 b with the aerosol-generating article being inserted in a direction from the second end 304 b towards the first end 304 a. The body 302 comprises a first portion 307 proximate the first end 304 a comprising a plurality of openings 306 and a second portion 309 between the first portion 307 and the second end 304 b.

FIG. 7 shows the retainer of FIG. 6 together with an aerosol-generating article 2 received within the retainer 300. The aerosol-generating article 2 has been received in the passage 305 such that the first portion 307 of the body 302 surrounds both the combustible heat source 4 and the aerosol-forming substrate 10 of the aerosol-generating article 2. The plurality of openings 306 formed in the first portion 307 of the body 302 therefore allow air to reach both the combustible heat source 4 and air inlets (not shown) formed in aerosol-generating article 2 in the region of the aerosol-forming substrate 10.

The openings 306 in first portion 307 of the body 302 which surrounds the combustible heat source 4 are defined by four prongs 318 equally spaced around the circumference of the body 302. The prongs 318 are bent over at the first end 304 a to partially close the first end 304 a. The openings 306 in first portion 307 of the body 302 which surrounds the combustible heat source 4 are such that about 90 percent of the exposed surface area of the combustible heat source 4 of the aerosol-generating article 2 remains exposed through the first end 304 a and the plurality of openings 306 in the first portion 307 of the body 302 when the aerosol-generating article 2 is received in the passage 305. The first portion 307 of the body 302 is made from stainless steel and the prongs 318 are angled inwards slightly into the passage 305 to minimise contact between the combustible heat source 4 and the body 302.

The body 302 has a substantially circular cross-section. The diameter of the body 302 is greater than the diameter of the aerosol-generating article 2 such that the ratio of the inner diameter of the first portion 307 of the body 302 to the outer diameter of the exposed surface of the combustible heat source 4 is at least about 1.2.

The second portion 309 of the body 302 is configured to be held by a user when the aerosol-generating article 2 is received in the passage 305. The second portion 309 is formed from PEEK or an elastomeric material, such as silicone or polyurethane.

FIG. 8A shows a cap 320 for the retainer 300 of FIG. 6 . The cap 320 comprises a hollow cylindrical body 322 having closed first end 324 a and an open second end 324 b. The cylindrical body 322 defines a longitudinal recess 326 for receiving the first portion 307 of the body 302 of the retainer 300. The length and internal diameter of the recess 326 are sized to completely receive, and to fit closely around the external surface of, the first portion 307 of the body 302 of the retainer 300. A proximal end of the cap 320 is configured to overlap a distal part of the second portion 309 of the body 302 of the retainer 300. The cap 320 is maintained in position on the retainer 300 by means of a snap-fit connection (not shown).

FIG. 8B is a longitudinal cross-section of the cap of FIG. 8A. The cap 320 has an inner layer 328 arranged inside the recess 326 and at a distal end of the recess 326. The inner layer conforms to the internal shape of the recess 326 and is configured to fit over the first portion 307 of the body 302 of the retainer 300. The inner layer 328 is formed from aluminium, which has a high thermal conductivity, and is arranged to absorb heat from the combustible heat source 4 to facilitate extinguishment of the combustible heat source 4. The inner layer 328 has a closed end 328 a which is substantially thicker than the remainder of the inner layer 328. The closed end 328 a is arranged to act as a heat sink for heat absorbed from the combustible heat source 4. The cylindrical body 322 of the cap 320 forms a second layer which is made from PEEK, which has a low thermal conductivity to reduce heat transfer to the outer surface of the cap 320, such that the cap 320 can be comfortably held by a user.

FIG. 9 shows the cap 320 of FIG. 8A attached to the retainer 300 of FIG. 6 together with an aerosol-generating article 2 received within the retainer 300. The cap 320 has been placed over the first portion 307 of the body 302 of the retainer 300. The plurality of openings (not visible) formed in the first portion 307 of the body 302 are covered by the cap such that the amount of air reaching the combustible heat source of the aerosol-generating article 2 is greatly reduced. In this arrangement, combustion can no longer be sustained and the combustible heat source is extinguished.

In use, an aerosol-generating article is inserted through the open end 304 b of the body 302 of the retainer 300. Indicia may be printed or formed on the outer surface of the aerosol-generating article 2 to indicate correct positioning of the aerosol-generating article 2 in the retainer 300. A user holds the combination of the retainer 300 and the aerosol-generating article 2 by the second portion 309 of the body 302 between their fingers and ignites the tip of the combustible heat source 4 through the plurality of openings 306 formed in the body 302. Once the combustible heat source 4 has been ignited, a user can take puffs on the aerosol-generating article 2. A thermochromic ink or coating may be applied to the outer surface of the body 302 to indicate to a user when the combustible heat source is at a temperature at which puffs can be commenced.

Once a user has finished taking puffs, the combustible heat source 4 can be extinguished by placing the cap 320 over the first portion 307 of the body 302 of the retainer 300 such that the plurality of openings 306 in the body 302 are covered by the cap 320. Once the combustible heat source 4 has been extinguished, the aerosol-generating article 2 can be removed from the retainer 300 and safely disposed of. A thermochromic ink or coating may be applied to the outer surface of the cap 320 to indicate when the temperature of the combustible heat source has dropped to a temperature indicative of the combustible heat source having been extinguished. The retainer 300 may be kept for use with another aerosol-generating article.

FIG. 10 shows a perspective view of a retainer 400 according to another embodiment of the present invention. The retainer 400 is very similar to the retainer 300 shown in FIG. 6 . The retainer 400 comprises a tubular body 402 having a partially-closed first end 404 a and an open second end 404 b. A longitudinal passage 405 for receiving an aerosol-generating article extends between the first end 404 a and the second end 404 b. The passage 405 is configured to receive an aerosol-generating article through the second end 404 b with the aerosol-generating article being inserted in a direction from the second end 404 b towards the first end 404 a. The body 402 comprises a first portion 407 proximate the first end 404 a comprising a plurality of openings 406 and a second portion 409 between the first portion 407 and the second end 404 b.

The passage 405 is configured such that the body 402 and an aerosol-generating article are moveable longitudinally relative to one another between a first position in which the first portion 407 of the body 402 surrounds the combustible heat source of the aerosol-generating article and a second position in which the second portion 409 of the body 402 surrounds the combustible heat source of the aerosol-generating article. The plurality of openings 406 in the first portion 407 are configured to permit airflow to the combustible heat source and the aerosol-forming substrate of the aerosol-generating article when the body 402 and the aerosol-generating article are in the first position. The second portion 409 is configured to inhibit combustion of the combustible heat source of the aerosol-generating article when the body 402 and the aerosol-generating article are in the second position.

The retainer 400 of FIG. 10 differs from the retainer 300 of FIG. 6 in that the second portion 409 comprises multiple layers. The second portion 409 comprises an inner layer (not shown) formed of aluminium which has a high thermal conductivity, and is arranged to absorb heat from the combustible heat source to facilitate extinguishment of the combustible heat source when the body and the aerosol-generating article are in the second position. The inner layer acts as a heat sink to absorb heat from the combustible heat source. The second portion 409 further comprises an outer layer 411 made from silicone or PEEK, which has a low thermal conductivity to reduce heat transfer to the outer surface of the second portion 409, such that the second portion 409 can be comfortably held by a user. A part of the outer layer 411 extends a distance beyond the inner layer (not shown) in a proximal direction. Since the outer layer 411 is formed from silicone, which is an elastomeric material, the extending part is able to grip an aerosol-generating article received in the passage 405.

FIGS. 11A and 11B show side views of a retainer similar to that of FIG. 10 in which an aerosol-generating article 2 has been received within the passage 405 of the retainer 400 and the second portion 409 of the body 402 of the retainer 400 is shown in first and second positions respectively. The retainer 400 of FIGS. 11A and 11B differs from that of FIG. 10 only in that it employs a different arrangement of openings 406 in the first portion 407 of the body 402.

FIG. 11A shows the second portion 409 of the body 402 of the retainer 400 in a first position in which the plurality of openings 406 in the first portion 407 of the body 402 surrounds the combustible heat source 4 of the aerosol-generating article 2. In the first position, air is free to reach the combustible heat source 4 of the aerosol-generating article 2, which underlies the openings 406 in the first portion of the body 402, so that the combustible heat source 4 can be ignited and combustion can be sustained.

FIG. 11B shows the second portion 409 of the body 402 of the retainer 400 in a second position in which the second portion 409 surrounds the combustible heat source (not visible) of the aerosol-generating article 2. In the second position, the amount of air reaching the combustible heat source of the aerosol-generating article 2 is significantly reduced because the second portion 409 of the body 402 is air impermeable. The amount of air reaching the combustible heat source is not sufficient to sustain combustion. The body 402 and the aerosol-generating article 2 can therefore be slid relative to one another into the second position to extinguish the aerosol-generating article 2. The aerosol-generating article 2 can be removed through the open end 404 b of the body 402 of the retainer 400 once the combustible heat source is extinguished.

In use, an aerosol-generating article 2 is inserted through the open end 404 b of the body 402 of the retainer 400 and the body and aerosol-generating article are slid relative to one another to the first position in which the plurality of openings 406 in the first portion 407 of the body 402 surrounds the combustible heat source 4 of the aerosol-generating article 2. Indicia may be printed or formed on the outer surface of the aerosol-generating article 2 to indicate correct positioning of the aerosol-generating article 2 in the retainer 400. A user holds the combination of the retainer 400 and the aerosol-generating article 2 by the second portion 409 of the body 402 between their fingers and ignites the tip of the combustible heat source 4 through the plurality of openings 406 formed in the body 402. Once the combustible heat source 4 has been ignited, a user can take puffs on the aerosol-generating article 2. A thermochromic ink or coating may be applied to the outer surface of the body 402 to indicate to a user when the combustible heat source is at a temperature at which puffs can be commenced.

Once a user has finished taking puffs, the combustible heat source 4 can be extinguished by sliding the body and aerosol-generating article relative to one another to the second position in which the second portion 409 surrounds the combustible heat source 4 of the aerosol-generating article 2. Once the combustible heat source 4 has been extinguished, the aerosol-generating article 2 can be removed from the retainer 400 and safely disposed of. A thermochromic ink or coating may be applied to the outer surface of the second portion 409 of the body 402 to indicate when the temperature of the combustible heat source has dropped to a temperature indicative of the combustible heat source having been extinguished. The retainer 400 may be kept for use with another aerosol-generating article.

FIG. 12 shows a perspective view of a retainer 500 according to another embodiment of the present invention and an aerosol-generating article 2 received within the retainer 500. The retainer 500 of FIG. 12 is identical to the retainer 300 of FIG. 6 with the exception that the second portion 509 of the body 502 comprises an opening 513 through which a user can contact the outer surface of the aerosol-generating article 2 when received in the passage. The retainer 500 of FIG. 12 is used in the same way as the retainer 300 of FIG. 6 except that the combination of the retainer 500 and aerosol-generating article 2 are gripped by the opening 513. Extinguishment of the combustible heat source 4 of the aerosol-generating article 2 is by means of a cap, for example, the cap 320 shown in FIG. 8A.

FIGS. 13A to 13C show perspective views of four alternative patterns 600 a to 600 c for forming the partially-closed first end 604 a and the openings 606 in the first portion of the tubular body 602 of a retainer according to the invention. The amount of the exposed surface of the combustible heat source which remains exposed through the openings 606 formed in the first portion of the tubular body 602 and partially-closed first end of the patterns 600 a to 600 c is at least 80 percent. The patterns 600 a to 600 c of FIGS. 13A to 13C can be used with any embodiment of retainer described herein.

FIG. 13D shows a perspective view of another pattern 600 d for forming the partially-closed first end 604 a and the openings 606 in the first portion of the tubular body 602 of a retainer. The amount of the exposed surface of the combustible heat source which remains exposed through the openings 606 formed in the first portion of the tubular body 602 and partially-closed first end of the pattern 600 d is about 50 percent.

The first ends 604 a of FIGS. 13A, 13C and 13D are partially closed by a plurality of prongs 618. The prongs 618 allow air to flow through the first end 604 a to the combustible heat source but prevent insertion or removal of the aerosol-generating article from the passage through the first end 604 a. Allowing air to flow through the first end 604 a to the combustible heat source facilitates lighting and sustained combustion of the combustible heat source. The prongs of at least FIGS. 13A and 13D are configured to contact the combustible heat source and act as a stop preventing further insertion of the aerosol-generating article. To minimise heat loss from the combustible heat source, the prongs 618 of FIGS. 13A and 13D are angled into the passage which receives the aerosol-generating article such that only the tips of the prongs 618 contact the combustible heat source.

FIG. 13B shows a different arrangement in which the first end 604 a is partially closed by cruciform shaped element arranged across the passage 605 at the first end 604 a which performs the same function as the prongs of FIGS. 13A, 13C and 13D.

EXAMPLES

The retainer should not significantly adversely impact the lighting time or the aerosol deliveries of the aerosol-generating article when used with an aerosol-generating article. To determine the impact of the retainer, example retainers according to the invention were prepared from stainless steel tube having the properties shown in Table 1 below. As indicated in Table 1, the example retainers were prepared with two different tube patterns formed in the first portion of the tubular body, that is tube pattern 600 c of FIG. 13C and tube pattern 600 d of FIG. 13D.

TABLE 1 Internal diameter Thickness Example No. (millimetre) (micrometre) Tube pattern 1 9.51 205 600d 2 9.50 250 600d 3 9.20 200 600d 4 10.4 300 600d 5 11.4 300 600d 6 9.51 205 600c 7 9.50 250 600c 8 9.20 200 600c 9 10.4 300 600c 10 11.4 300 600c The example retainers of Table 1 were used with a reference aerosol-generating article. The impact of using the example retainers with the reference aerosol-generating article was compared to the performance of the reference aerosol-generating article being used without a retainer. The properties of the reference aerosol-generating article are shown in Table 2 below.

TABLE 2 Reference aerosol-generating article Total stick length 70 millimetres Outer diameter 7.80 millimetres Tobacco plug length 9 millimetres Combustible heat source length 9 millimetres

Impact of Tube Pattern on Lighting Time

To assess the impact of the tube pattern of the example retainers on the lighting time of an aerosol-generating article, the percentage of the exposed surface area of the combustible heat source of the aerosol-generating article that remains exposed through the first end and the plurality of openings in the first portion of the body when the aerosol-generating article is received in the passage was calculated. In the reference aerosol-generating article, a length of 5.5 millimetres of the combustible heat source is exposed and is available for burning. As mentioned above, the percentage is calculated by considering the total external surface of the tubular body over the portion of the combustible heat source burning zone. The percentage is the percentage of the tubular body surface that has been removed by forming the openings and partially closed first end versus the total surface of the tubular body covering the exposed surface area of the heat source.

To determine the lighting time of the combustible heat source, a reference aerosol-generating passage was received within the passage of the tubular body of each of the example retainers and a yellow flame was applied to the tubular body over the combustible heat source. The lighting time was determined by measuring the amount of time which elapsed between the time at which the yellow flame was applied and the time at which it was visually observed that ignition was starting to propagate through the heat source. The lighting time was measured using a stopwatch. The results are shown in Table 3 below.

As can be seen from Table 3, the average percentage of the combustible heat source (CHS) that remains exposed through the openings formed in the first portion of the tubular body and the partially-closed first end for Examples 1 to 5 is approximately 50 percent and for Examples 6 to 10 is approximately 80 percent. As shown in Table 1, Examples 1 to 5 all have tube pattern 600 d and Examples 6 to 10 all have tube pattern 600 c. Although Examples 1 to 5 all have the same tube pattern, it can be seen from Table 3 that there are small differences between the percentages for Examples 1 to 5. These are due to manufacturing tolerances in forming the openings and partially-closed first end and are acceptable. The same applies to Examples 6 to 10.

TABLE 3 Percent of CHS that Average remains exposed lighting time Example through openings [seconds] Reference n/a 1.9 1 50 percent 16.9 2 51 percent 13.9 3 50 percent 17.3 4 52 percent 21.9 5 53 percent 12.7 6 81 percent 4.2 7 81 percent 3.4 8 80 percent 5.1 9 83 percent 4.4 10 84 percent 4.0

Table 3 shows that Examples 6 to 10, in which about 80 percent of the exposed surface area of the combustible heat source remains exposed through the openings, exhibit a lighting time of about 5 seconds or less. This is considered an acceptable lighting time because it will not unduly delay a user's use of the aerosol-generating article compared to the lighting time of the reference aerosol-generating article alone, that is without a retainer. Table 3 also shows that Examples 1 to 5, in which about 50 percent of the exposed surface area of the combustible heat source remains exposed through the openings, exhibit significantly longer and unacceptable lighting times. Therefore, providing a retainer in which the percentage of the exposed surface of the combustible heat source which remains exposed through the openings formed in the first portion of the tubular body and partially-closed first end, will not significantly adversely impact the lighting time of the combustible heat source.

Impact of Tube Diameter on Aerosol Deliveries and Temperature

Example retainers 7, 8, 9 and 10 were used to assess the impact of the internal diameter of the tubular body on aerosol deliveries compared to aerosol deliveries from the reference aerosol-generating article alone, that is without a retainer. Each of these example retainers has the same tube pattern, that is tube pattern 600 c of FIG. 13C. The percentage of the exposed surface of the combustible heat source which remains exposed through the openings formed in the first portion of the tubular body and partially-closed first end is about 80 percent and is constant across all four examples. The internal diameter and thickness of the tubular body varies in each of the example retainers as shown in Table 1 above and in Table 4 below. However, as discussed further below, it was found that the thickness of the tubular body had no impact on aerosol deliveries for the range of thicknesses examined. Therefore, the results of this test show the impact on aerosol deliveries from varying internal diameter only.

The impact of varying the diameter of the tubular body on aerosol deliveries was measured. In particular, the impact on the amount of glycerine, nicotine and total particulate matter (TPM) was measured. Total particulate matter is a measure of the total amount of aerosol produced during a puff and includes the amounts of glycerine and nicotine produced. The results were compared against the reference aerosol-generating article and are shown in Table 4 below.

TABLE 4 Internal Thickness Glycerine Nicotine TPM Diameter (micro- (milli- (milli- (milli- Example (millimetres) metres) grams) grams) grams) Reference n/a n/a 4.1 1.06 18.42 7 9.5 250 4.8 1.03 21.9 8 9.2 200 4.2 0.94 19.3 9 10.4 300 3.5 0.78 22.6 10 11.4 300 4.6 0.98 23.6

As can be seen from Table 4, none of example retainers 7 to 10 significantly adversely affect aerosol deliveries when used with an aerosol-generating article. Indeed, compared to the reference aerosol-generating article, the use of a retainer with an aerosol-generating article was actually found to improve aerosol deliveries at least with respect to total particulate matter. The results in Table 4 show that total particulate matter deliveries increase with increasing diameter.

The effect of varying the internal diameter of the tubular body of example retainers 7 to 10 on the temperature within the aerosol-forming substrate was also assessed. As discussed further below, it was found that the thickness of the tubular body had no impact on the temperature within the aerosol-forming substrate for the range of thicknesses examined. Therefore, the results of this test show the impact on temperature from varying internal diameter only.

To measure the temperature within the aerosol-forming substrate a thermocouple was inserted into the aerosol-forming substrate at a distance of 7 millimetres from the interface of the aerosol-forming substrate and combustible heat source. The results are shown in FIG. 14 .

As can be seen from FIG. 14 , the temperature in the tobacco plug (that is, the aerosol-forming substrate) is increasing with the diameter of the tubular body in the range 9.2 millimetres to 11.4 millimetres, which the inventors believe produces the increase in aerosol deliveries.

It has been surprisingly found that the heat generated by the combustible heat source is better preserved due to the presence of the retainer. A proportion of the heat, that would otherwise be lost to the ambient air, is transferred to the tubular body and transferred back to the aerosol-generating article through radiation from the tubular body and/or air convection. As a consequence, the temperature in the aerosol-generating article is higher than it would otherwise be without a retainer present. Due to the same effect, the temperature at the proximal part of the combustible heat source could also be higher. In which case, the heat transferred to the aerosol-forming substrate by conduction would be increased.

Impact of Tube Thickness on Aerosol Deliveries and Temperature

To assess the impact of the thickness of the tubular body of the retainer on aerosol deliveries and temperature, four further example retainers (example retainers 11 to 14) were prepared having stainless steel tubular bodies of the same diameter but different thicknesses ranging from 40 micrometres to 300 micrometres as shown in Table 5 below.

The impact of varying the thickness of the tubular body on aerosol deliveries was measured. In particular, the impact on the amount of glycerine, nicotine and total particulate matter (TPM) was measured. The results were compared against the reference aerosol-generating article and are shown in Table 5 below.

As can be seen from Table 5, example retainers 11 to 14 result in general increased aerosol deliveries when used with an aerosol-generating article compared to the reference aerosol-generating article alone. The increase is due to the presence of the tubular body of the example retainers, which have an internal diameter of 11 millimetres. There is no clear impact of the thickness of the tubular body on aerosol deliveries in the range of thickness examined.

TABLE 5 Internal Thickness Glycerine Nicotine TPM Diameter (micro- (milli- (milli- (milli- Example (millimetres) metres) grams) grams) grams) Reference n/a n/a 4.1 1.06 18.4 11 11.0 40 5.2 1.04 22.9 12 11.0 80 5.4 1.10 23.1 13 11.0 100 5.9 1.15 24.7 14 11.4 300 5.2 1.14 24.0

The effect of varying the thickness of the tubular body of example retainers 11 to 14 on the temperature within the aerosol-forming substrate was also assessed. To measure the temperature within the aerosol-forming substrate a thermocouple was inserted into the aerosol-forming substrate at a distance of 7 millimetres from the interface of the aerosol-forming substrate and combustible heat source. The results are shown in FIG. 15 .

As can be seen from FIG. 15 , the temperature in the tobacco plug (that is, the aerosol-forming substrate) is higher for all of example retainers 11 to 14 compared to the reference aerosol-generating article. Again, the increase is due to the presence of the tubular body of the example retainers, which have an internal diameter of 11 millimetres. There is no clear impact of the thickness of the tubular body on temperature in the range of thicknesses examined.

It will be appreciated that, to enhance the mechanical stability of the tubular body of the retainer, the tube thickness would be preferably between 100 micrometres and 250 micrometres. 

1. A kit comprising: an aerosol generating article comprising a combustible heat source and an aerosol-forming substrate; and a retainer for the aerosol generating article, the retainer comprising: a tubular body having a partially-closed first end and an open second end, wherein the body defines a longitudinal passage extending between the first end and the second end and wherein the body comprises: a first portion proximate the first end comprising a plurality of openings; and a second portion between the first portion and the second end, wherein the body is configured to at least partially receive the aerosol-generating article in the passage such that the first portion of the body surrounds the combustible heat source of the aerosol-generating article, wherein the first end and the first portion of the body are configured such that at least about 80 percent of the exposed surface area of the combustible heat source of the aerosol-generating article remains exposed through the first end and the plurality of openings in the first portion of the body when the aerosol-generating article is received in the passage such that the first portion of the body surrounds the combustible heat source of the aerosol-generating article, and wherein the ratio of the inner diameter of the first portion of the body to the outer diameter of the exposed surface of the combustible heat source is at least about 1.1.
 2. The kit according to claim 1 wherein between about 80 percent and about 90 percent of the exposed surface area of the combustible heat source of the aerosol-generating article remains exposed through the first end and the plurality of openings in the first portion of the body when the aerosol-generating article is received in the passage such that the first portion of the body surrounds the combustible heat source of the aerosol-generating article.
 3. The kit according to claim 1 wherein the ratio of the inner diameter of the first portion of the body to the outer diameter of the exposed surface of the combustible heat source is at least about 1.16.
 4. The kit according to claim 3 wherein the ratio of the inner diameter of the first portion of the body to the outer diameter of the exposed surface of the combustible heat source is between about 1.16 and about 1.6.
 5. The kit according to claim 1 wherein the ratio of the inner diameter of the first portion of the body to the outer diameter of the exposed surface of the combustible heat source is at least about 1.2.
 6. The kit according to claim 1 wherein the body is configured to at least partially receive the aerosol-generating article in the passage such that the first portion of the body surrounds the combustible heat source and the aerosol-forming substrate of the aerosol-generating article.
 7. The kit according to claim 1 wherein the second portion of the body is configured to be held by a user when the aerosol-generating article is received in the passage such that the first portion of the body surrounds the combustible heat source of the aerosol-generating article.
 8. The kit according to claim 1 wherein the second portion of the body comprises an outer layer having a thermal conductivity of 0.5 Wm-1K-1 or less.
 9. The kit according to claim 1 wherein the second portion of the body comprises an opening through which a user can contact the outer surface of the aerosol-generating article when received in the passage.
 10. The kit according to claim 1 further comprising a thermal indicator provided on an outer surface of the body, wherein the thermal indicator comprises at least one reversible thermochromic material that undergoes a reversible visible colour change when the temperature of the thermal indicator rises to a switching temperature.
 11. The kit according to claim 1 further comprising an air impermeable cap, wherein the cap is configured to fit over the first end and the first portion of the body of the retainer.
 12. The kit according to claim 11 wherein the cap comprises an inner layer having a thermal conductivity of at least 120 Wm-1K-1.
 13. The kit according to claim 11 wherein the cap comprises an outer layer having a thermal conductivity of 0.5 Wm-1K-1 or less.
 14. The kit according to claim 11 wherein the cap comprises one or more phase-change materials.
 15. The kit according to claim 11 wherein the cap and the first portion of the body of the retainer are configured to be detachably coupled to one another via a snap-fit connection. 